The place where those black boxes were situated it was impossible to reach. What I understand it was in some deep canyon.That is why the FAA needs to mandate that all black boxes on trans oceanic flights should be equipped with floatation device.Many military aircraft are already equipped with ejectable/deployable flight data recorders and recovery beacons designed to float indefinitely
If we can hear the box ping, the box could hear us ping too, if it were so designed. There ought to be a way of downloading at least an abridged version of its contents through a sonic link if it cannot be physically retrieved.